Le 24/3/16 17:48, Denis Kudriashov a écrit :
Hello.
I finished new version of Ghost:
* DNU approach for basic proxies instead of #cannotInterpret: trick
(trick used only for class proxies)
Does it mean that we cannot proxy classes?
* Abstract proxy classes uses Ghost name instead of Proxy: there are
GHObjectGhost and GHClassGhost.
* GHProxyHandler renamed to GHGhostBehaviour. Concrete ghosts should
implement #ghostBehaviour instead of #proxyHandler.
* GHGhostBehaviour should define #currentMetaLevel to specify set of
messages which should not be intercepted. Such meta messages will
be executed under ghost instance by subclass of GHMetaMessages.
In previous version there was dictionary which maps meta message
selector to implementation selector. It was not suitable. Now meta
messages should be directly implemented on particular
GHMetaMessages subclass and all it methods are considered meta.
So GhostBehaviour should return instance of GHMetaLevel with meta
messages implementation class:
o GHMetaLevel with: GHEmptyMetaMessages "when all possible
messages should intercepted"
o GHMetaLevel with: GHStandartMetaMessages "when tools specific
messages should not be intercepted"
For example standard meta messages implements #inspect:
GHStandartMetaMessages>>inspect
"Create and schedule an Inspector in which the user can
examine the receiver's variables."
^ Smalltalk tools inspector inspect: *ghost*
* Traits for methods explicitly defined on ghosts: TMinimalProxy,
TNotNilProxy, TIdentifiedProxy (with #=, #hash, #class). Concrete
proxies can add this traits to itself independently from meta
level. For example traits supply convenient methods to retrieve
ghost information in polymorphic way with objects:
o ghost isGhost
o ghost ghostClass "returns actual class of receiver"
o ghost ghostPrintString "returns string which represents ghost
from meta level point of view"
This traits are suitable and they provide some kind of
optimisation for proxies (methods from traits are executed
directly instead of complex meta messages mechanizm). But maybe
they are superfluous. For example they can't be reused for class
proxies which substitute real object classes (to intercept all
instance messages).
* GHClassGhost able to replace class of real objects. It implements
cannotInterpret: trick to intercept all instance messages.
Subclasses should define two behaviours: #ghostBehaviour (as any
other ghost) and #instancesBehaviour which will process instance
messages. In previous version it was different message to same
#ghostBehaviour.
* New kind of proxies:
o GHObjectVirus. It is special kind of GHClassProxy. It infects
real object to intercept it messages. From meta level infected
object looks like healthy object which means that meta
messages are executed by infected object itself. As class
virus looks like real victim class. So in case when virus is
created with standard meta level tools will not differ him
from health object. There are special messages which allow ask
object about viruses:
+ infectedObject isInfectedByVirus
+ infectedObject virus
+ infectedObject recoverFromVirus
o GHLearningObject. It is suitable proxy which retrieves all
unknown methods from teacher class. Thank's Stephan for this idea.
This kind of proxy allows me easily find required set of
messages to support inspectors and debuggers. You can create
instance of learning object by:
GHLearningObject withTeacher: Object.
And any operation with it will fill studiedMessages
dictionary. In my case I opened GTInspector on it and got all
messages which was needed for him.
* Ghosts works correctly with latest Pharo 5 tools (basic inspector,
GTInspector, SpecDebugger, GTDebugger). Required methods for tools
are extracted to 'Ghost-GTSupport' package.
* Repackaging:
o Ghost-ObjectProxies. It contains all core classes and abstract
GHObjectGhost which is based on DNU
o Ghost-ClassProxies. It contains code for proxy which can
substitute class of real object. GHClassGhost implements
cannotInterpret: trick to intercept all instance messages. And
it implement support for debugging such methods.
o Ghost-LearningObject
o Ghost-ObjectVirus
o Ghost-GTSupport
o test packages
* All code moved to Pharo repository
http://smalltalkhub.com/#!/~Pharo/Ghost
<http://smalltalkhub.com/#%21/%7EPharo/Ghost> (in includes
packages from CAR repo too)
You can load new version by:
Gofer it
smalltalkhubUser: 'Pharo' project: 'Ghost';
configurationOf: 'Ghost';
loadStable
I use it now in Seamless and Mocketry.
